Methods for forming a transition metal nitride film on a substrate by atomic layer deposition and related semiconductor device structures

ABSTRACT

Methods for forming a transition metal nitride film on a substrate by atomic layer deposition and related semiconductor device structures are provided. In some embodiments, methods may include contacting a substrate with a first vapor phase reactant comprising a transition metal precursor and contacting the substrate with a second vapor phase reactant comprising an alkyl-hydrazine precursor. In some embodiments, related semiconductor device structures may include a PMOS transistor gate structure, the PMOS transistor gate structure including a transition metal nitride film and a gate dielectric between the transition nitride film and a semiconductor body. The transition metal nitride film includes a predominant (200) crystallographic orientation.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 15/711,989, filed on Sep. 21, 2017 and entitled “METHODS FOR FORMINGA TRANSITION METAL NITRIDE FILM ON A SUBSTRATE BY ATOMIC LAYERDEPOSITION AND RELATED SEMICONDUCTOR DEVICE STRUCTURES,” which claimsthe benefit of U.S. Provisional Patent Application No. 62/415,842, filedon Nov. 1, 2016 and entitled “METHODS FOR FORMING A TRANSITION METALNITRIDE FILM ON A SUBSTRATE BY ATOMIC LAYER DEPOSITION AND RELATEDSEMICONDUCTOR DEVICE STRUCTURES,” the disclosures of which areincorporated herein by reference.

BACKGROUND Field of the Invention

The present disclosure relates generally to methods for forming atransition metal nitride film on a substrate by atomic layer depositionand related semiconductor device structures.

Description of the Related Art

Metal-oxide-semiconductor (MOS) technology has conventionally utilizedn-type doped polysilicon as the gate electrode material. However, dopedpolysilicon may not be an ideal gate electrode material for advancednode applications. For example, although doped polysilicon isconductive, there may still be a surface region, which can be depletedof carriers under bias conditions. This region may appear as an extragate insulator thickness, commonly referred to as gate depletion, andmay contribute to the equivalent oxide thickness. While the gatedepletion region may be thin, on the order of a few angstroms (Å), itmay become significant as the gate oxide thicknesses are reduced inadvance node applications. As a further example, polysilicon does notexhibit an ideal effective work function (eWF) for both NMOS and PMOSdevices. To overcome the non-ideal effective work function of dopedpolysilicon, a threshold voltage adjustment implantation may beutilized. However, as device geometries reduce in advanced nodeapplications, the threshold voltage adjustment implantation processesmay become increasingly complex and impractical.

To overcome the problems associated with doped polysilicon gateelectrodes, the non-ideal doped polysilicon gate material may bereplaced with an alternative material, such as, for example, atransition metal nitride. For example, the properties of a transitionmetal nitride may be modified to provide a gate electrode structure witha more ideal effective work function for both the NMOS and PMOS devices,where the effective work function of the gate electrode, i.e., theenergy needed to extract an electron, must be compatible with thebarrier height of the semiconductor material. For example, in the caseof PMOS devices, the required effective work function is approximately5.0 eV.

Atomic layer deposition (ALD) may be utilized for the deposition oftransition metal nitride films, such as, for example, tantalum nitride(TaN), titanium nitride (TiN), tungsten nitride (WN) and niobium nitride(NbN). However, the modification of the electronic or crystallographicproperties of ALD formed transition metal nitride films using knownprecursors may be limited due to the self-limiting nature of the ALDprocess.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form. These concepts are described in further detail in thedetailed description of example embodiments of the disclosure below.This summary is not intended to identify key features or essentialfeatures of the claimed subject matter, nor is it intended to be used tolimit the scope of the claimed subject matter.

In some embodiments, methods for forming a transition metal nitride filmon a substrate by atomic layer deposition are provided. The methods maycomprise contacting the substrate with a first vapor phase reactantcomprising a transition metal precursor and contacting the substratewith a second vapor phase reactant comprising an alkyl-hydrazineprecursor.

In some embodiments, semiconductor device structures are provided. Thesemiconductor device structures may comprise a PMOS transistor gatestructure, the PMOS transistor gate structure comprising a transitionmetal nitride film and a gate dielectric between the transition metalnitride film and a semiconductor body. In some embodiments, thetransition metal nitride film comprises a predominant (200)crystallographic orientation.

For the proposes of summarizing the invention and the advantagesachieved over the prior art, certain objects and advantages of theinvention have been described herein above. Of course, it is to beunderstood that not necessarily all such objects or advantages may beachieved in accordance with any particular embodiment of the invention.Thus, for example, those skilled in the art will recognize that theinvention may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught or suggestedherein without necessarily achieving other objects or advantages as maybe taught or suggested herein.

All of the embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to attached figures,the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming what are regarded as embodiments of theinvention, the advantages of embodiments of the disclosure may be morereadily ascertained from the description of certain examples ofembodiments of the disclosure when read in conjunction with theaccompanying drawings, in which:

FIG. 1 is a graph showing x-ray diffraction (XRD) scans of titaniumnitride films formed according to the embodiments of the disclosure.

FIG. 2 is simplified cross section view of a semiconductor devicestructure formed according to the embodiments of the disclosure.

FIG. 3 is a graph showing the effective work function (eWF) of variousgate electrode structures comprising a titanium nitride film as afunction of titanium nitride film thickness.

FIG. 4 illustrates a reaction system configured to perform embodimentsof the disclosure.

DETAILED DESCRIPTION

The illustrations presented herein are not meant to be actual view ofany particular material, structure, or device, but are merely idealizedrepresentations that are used to describe embodiments of the disclosure.

As used herein, the term “atomic layer deposition” (ALD) may refer to avapor deposition process in which deposition cycles, preferably aplurality of consecutive deposition cycles, are conducted in a processchamber. Typically, during each cycle the precursor is chemisorbed to adeposition surface (e.g., a substrate surface or a previously depositedunderlying surface such as material from a previous ALD cycle), forminga monolayer or sub-monolayer that does not readily react with additionalprecursor (i.e., a self-limiting reaction). Thereafter, if necessary, areactant (e.g., another precursor or reaction gas) may subsequently beintroduced into the process chamber for use in converting thechemisorbed precursor to the desired material on the deposition surface.Typically, this reactant is capable of further reaction with theprecursor. Further, purging steps may also be utilized during each cycleto remove excess precursor from the process chamber and/or remove excessreactant and/or reaction byproducts from the process chamber afterconversion of the chemisorbed precursor. Further, the term “atomic layerdeposition,” as used herein, is also meant to include processesdesignated by related terms such as, “chemical vapor atomic layerdeposition,” “atomic layer epitaxy” (ALE), molecular beam epitaxy (MBE),gas source MBE, or organometallic MBE, and chemical beam epitaxy whenperformed with alternating pulses of precursor composition(s), reactivegas, and purge (e.g., inert carrier) gas.

As used herein, the term “substrate” may refer to any underlyingmaterial or materials that may be used, or upon which a device, acircuit or a film may be formed.

As used herein, the term “alkyl-hydrazine” may refer to a derivative ofhydrazine (N₂H₄) which may comprise an alkyl functional group and mayalso comprise additional functional groups.

The present disclosure includes methods and device structures that maybe used to form a transition metal nitride film or comprise a transitionmetal nitride film. The existing precursors that may be utilized in theALD of transition metal nitride films may have limitations due to theirinability to tune certain characteristics of the ALD transition metalnitride film; such characteristics may include the effective workfunction and the crystallographic orientation. For example, it is knownthat the effective work function of a gate electrode may vary as afunction of its thickness, i.e., the effective work function of the gateelectrode may decrease or increase with decreasing thickness of thematerials comprising the gate electrode. As device geometries decreasein advanced node applications, the thickness of the corresponding devicefilms, for example, such as the gate electrode, may also decrease with acorresponding change in the effective work function of the film. Such achange in the effective work function of the gate electrode at reducedthickness may result in a non-ideal effective work function for NMOS andPMOS device structures. Methods and structures are therefore required toprovide a more desirable transition metal nitride film. Examples of suchmethods and structures are disclosed in further detail below.

ALD is based on typically self-limiting reactions, whereby sequentialand alternating pulses of reactants are used to deposit about one atomic(or molecular) monolayer of material per deposition cycle. Thedeposition conditions and precursors are typically selected to provideself-saturating reactions, such that an adsorbed layer of one reactantleaves a surface termination that is non-reactive with the gas phasereactants of the same reactant. The substrate is subsequently contactedwith a different reactant that reacts with the previous termination toenable continued deposition. Thus, each cycle of alternated pulsestypically leaves no more than about one monolayer of the desiredmaterial. However, as mentioned above, the skilled artisan willrecognize that in one or more ALD cycles more than one monolayer ofmaterial may be deposited, for example, if some gas phase reactionsoccur despite the alternating nature of the process.

In an ALD-type process for depositing transition metal nitride films,one deposition cycle comprises exposing the substrate to a firstreactant, removing any unreacted first reactant and reaction byproductsfrom the reaction space, exposing the substrate to a second reactant,followed by a second removal step. The first reactant may comprise ametal precursor, in particular a transition metal precursor, such as atitanium precursor, and the second reactant may comprise analkyl-hydrazine precursor, such as, for example, at least one oftertbutylhydrazine (C₄H₉N2H₃), methylhydrazine (CH₃NHNH₂),dimethylhydrazine ((CH₃)₂N₂H₂).

The transition metal precursor or compound may comprise at least one ofthe transition metals selected from the group comprising scandium (Sc),yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V),niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten(W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium(Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni),palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc(Zn), cadmium (Cd) or mercury (Hg). However, as titanium nitride filmsare exemplified herein, in such embodiments, the metal compound maycomprise titanium.

As a non-limiting example embodiment, a transition metal halidereactant, such as, e.g., titanium tetrachloride (TiCl₄), may be used asthe transition metal precursor in ALD processes.

Precursors may be separated by inert gases, such as argon (Ar) ornitrogen (N₂), to prevent gas-phase reactions between reactants andenable self-saturating surface reactions. In some embodiments, however,the substrate may be moved to separately contact a first metal reactantand a second alkyl-hydrazine reactant. Because the reactionsself-saturate, strict temperature control of the substrates and precisedosage control of the precursors is not usually required. However, thesubstrate temperature is preferably such that an incident gas speciesdoes not condense into monolayers nor decompose on the surface. Surpluschemicals and reaction byproducts, if any, are removed from thesubstrate surface, such as by purging the reaction space or by movingthe substrate, before the substrate is contacted with the next reactivechemical. Undesired gaseous molecules can be effectively expelled from areaction space with the help of an inert purging gas. A vacuum pump maybe used to assist in the purging.

According to some embodiments, ALD-type processes are used to formtransition metal nitride films, for example, titanium nitride films on asubstrate, such as an integrated circuit workpiece. Preferably, each ALDcycle comprises two distinct deposition steps or phases. In a firstphase of the deposition cycle (“the metal phase”), the substrate surfaceon which deposition is desired is contacted with a first reactantcomprising a transition metal such as titanium (i.e., titanium sourcematerial or chemical) which chemisorbs onto the substrate surface,forming no more than about one monolayer of reactant species on thesurface of the substrate.

In some embodiments, the transition metal (e.g., titanium) sourcechemical, also referred to herein as the “transition metal compound” (orin some embodiments as the “titanium compound”), is a halide and theadsorbed monolayer is terminated with halogen ligands. In someembodiments, the titanium halide may be titanium tetrachloride (TiCl₄).

Excess transition metal (e.g., titanium) source material and reactionbyproducts (if any) may be removed from the substrate surface, e.g., bypurging with an inert gas. Excess transition metal source material andany reaction byproducts may be removed with the aid of a vacuumgenerated by a pumping system.

In a second phase of the deposition cycle (“the nitrogen phase”), thesubstrate is contacted with an alkyl-hydrazine. In some embodiments thealkyl-hydrazine may comprise at least one of tertbutylhydrazine,methylhydrazine, dimethylhydrazine. The second alkyl-hydrazine reactantmay react with the titanium-containing molecules left on the substratesurface. Preferably, in the second phase nitrogen is incorporated intothe film by the interaction of the second alkyl-hydrazine reactant withthe monolayer left by the transition metal (e.g., titanium) sourcematerial. In some embodiments, reaction between the secondalkyl-hydrazine reactant and the chemisorbed transition metal speciesproduces a transition metal nitride thin film over the substrate.

Excess second source chemical and reaction byproducts, if any, areremoved from the substrate surface, for example by a purging gas pulseand/or vacuum generated by a pumping system. Purging gas is preferablyany inert gas, such as, without limitation, argon (Ar), nitrogen (N₂) orhelium (He). A phase is generally considered to immediately followanother phase if a purge (i.e., purging gas pulse) or other reactantremoval step intervenes.

FIG. 1 is a graph showing the 2 theta x-ray diffraction (XRD) scans ofexample titanium nitride films formed by ALD process of the currentdisclosure utilizing a transition metal precursor and an alkyl-hydrazineprecursor. For example, the XRD scan denoted by the label 100 is takenfrom a titanium nitride film formed by ALD utilizing titaniumtetrachloride and an alkyl-hydrazine at a substrate temperature of 350°C. The XRD scan denoted by label 100 indicates that transition metalnitride films, such as, for example, titanium nitride, formed by themethods of the disclosure may comprise a number of crystallographicorientations including (111), (200), (220), (311) and (420) orientationswith the (200) crystallographic orientation being predominant.Therefore, in some embodiments of the disclosure, the transition metalnitride film, formed by the ALD processes described herein, comprises a(200) crystallographic orientation and in some embodiments thetransition metal nitride film comprises a predominant (200)crystallographic orientation.

In some embodiments of the disclosure, forming the transition metalnitride film may comprise forming the transition metal nitride film to athickness of less than 50 Angstroms, or to a thickness of less than 30Angstroms, or to a thickness of less than 20 Angstroms. As anon-limiting example embodiment of the disclosure, forming thetransition metal nitride film may comprise forming a titanium nitridefilm to a thickness of less than 30 Angstroms.

The utilization of an alkyl-hydrazine precursor as the nitrogen sourcein the ALD processes described herein may allow for the formation oftransition metal nitride films, such as titanium nitride, with anincreased atomic percentage of carbon and hydrogen. The ability toincorporate increased atomic percentages of carbon and hydrogen into thetransition metal nitride film may allow the ability to modify thecharacteristics of the ALD transition metal nitride film. For example,in some embodiments methods may comprise forming the transition metalnitride film to have an atomic concentration of carbon greater than0.1%, or greater than 0.5%, or greater than 1%, or even greater than10%. In addition, in some embodiments, methods may comprise forming thetransition metal nitride film to have an atomic concentration ofhydrogen greater than 0.1%, or greater than 1%, or greater than 2%, oreven greater than 10%. In the embodiments outlined herein, the atomicconcentration of an element may be determined utilizing Rutherfordbackscattering (RBS).

The ALD processes described herein, utilizing a transition metalprecursor and an alkyl-hydrazine precursor, may be performed in an ALDdeposition system with a heated substrate. For example, in someembodiments, methods may comprise heating the substrate to temperatureof greater than 300° C. In some embodiments, methods may compriseheating the substrate to temperature of greater than 350° C. In otherembodiments, methods may comprise heating the substrate to temperatureof greater than 450° C.

The deposition rate of the thin film by ALD, which is typicallypresented as A/pulsing cycle, depends on a number of factors including,for example, on the number of available reactive surface sites or activesites on the surface and bulkiness of the chemisorbing molecules. Insome embodiments, the deposition rate of such films may range from about0.1 to about 5.0 Å/pulsing cycle. In some embodiments, the depositionrate can be about 0.1, 0.2, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0,4.5, or 5.0 Å/pulsing cycle.

The transition metal nitride thin films, such as titanium nitride thinfilms, formed by the ALD processes disclosed herein can be utilized in avariety of contexts, such as in the formation of gate electrodestructures. One of skill in the art will recognize that the processesdescribed herein are applicable to many contexts, including fabricationof PMOS transistors including planar devices as well as multiple gatetransistors, such as FinFETs.

As a non-limiting example, and with reference to FIG. 2, a semiconductordevice structure 300 may comprise a transistor structure and may includea source region 302, a drain region 304, a channel region 306 therebetween. A transistor gate structure 308 may comprise a gate electrode310 which may be separated from the channel region 306 by a gatedielectric 312. According to the teaching of the present disclosure, thegate electrode 310 may comprise a transition metal nitride film, such astitanium nitride, formed by an atomic layer deposition process utilizinga transition metal precursor and an alkyl-hydrazine precursor. As shownin FIG. 2, in some embodiment the transistor gate structure 308 mayfurther comprise one or more additional conductive layers 314 formed onthe gate electrode 310. The one or more additional conductive layers 314may comprise at least one of polysilicon, a refractory metal, atransition metal carbide, and a transition metal nitride.

In some embodiments, the semiconductor device structure 300 may comprisea PMOS transistor. The PMOS transistor may further comprise thetransistor gate structure 308. The PMOS transistor gate structure 308may comprise a gate electrode 310 comprising a transition metal nitridefilm and a gate dielectric 312 between the transition metal nitride filmand a semiconductor body 316. In some embodiments, the semiconductordevice structure 300 may comprise a NMOS transistor. The NMOS transistormay further comprise the transistor gate structure 308. The NMOStransistor gate structure 308 may comprise a gate electrode 310comprising a transition metal nitride film and a gate dielectric 312between the transition metal nitride film and a semiconductor body 316.

In some embodiments, the gate electrode 310, may comprise a transitionmetal nitride film, such as, for example, titanium nitride, tantalumnitride, tungsten nitride, and niobium nitride. In some embodiments thegate electrode 310, may comprise a transition metal nitride film, suchas titanium nitride, and may comprise a predominant (200)crystallographic orientation.

In some embodiments of the disclosure, the additional conductive layers314 may have an inherently lower effective work function and one of thepurposes of the gate electrode 310 may be to modulate the effective workfunction of the transistor gate structure 308. For example, theeffective work function of the additional conductive layers 314 may beapproximately 4.2 eV and the gate electrode 310 may be utilized tomodulate the effective work function of the transistor gate structure308. In some embodiments, the properties (e.g., composition andthickness) of the gate electrode 310 may be adapted in order tocontrollably modulate the effective work function of the transistor gatestructure 308 between approximately 4.2 eV and approximately 4.8 eV. Asa non-limiting example embodiment, the thickness and the carbon contentof the gate electrode 308 may be adapted to provide an optimizedeffective work function for an NMOS transistor structure. For example,in some embodiments of the disclosure, the gate electrode 310 may have athickness of less than 10 Angstroms and a carbon content of less than10%, which may result in an effective work function of the transistorgate structure 308 of approximately 4.6 eV.

In some embodiments of the disclosure, the properties of the gateelectrode 310 may be tailored to controllably module the effective workfunction of the transistor gate structure 308 in order to effectivelytune the threshold voltage (V_(th)) of a PMOS transistor and/or an NMOStransistor. For example, the effective work function of the transistorgate structure may be varied in order to fabricate a complementarymetal-oxide-semiconductor (CMOS) integrated circuit, comprising aplurality of NMOS transistors and PMOS transistors, with multiplethreshold voltages (V_(th)), commonly referred to as multi-thresholdCMOS (MTCMOS).

As a non-limiting example embodiment, FIG. 3 is a graph showing theeffective work function (eWF) of various gate electrode structurescomprising a titanium nitride film as a function of the titanium nitridefilm thickness. In these non-limiting example embodiments the gateelectrode structure 308 comprises a hafnium oxide gate oxide 312, atitanium nitride gate electrode 310 and one or more additionalconductive layers 314 comprising titanium aluminum carbide and titaniumnitride.

The eWF line labelled as 200 indicates the eWF of a gate electrodestructure comprising a titanium nitride film formed by ALD utilizing thecommon prior art precursor ammonia (NH₃) as the nitrogen source. The eWFline labelled as 210 indicates the eWF of a gate electrode structurecomprising a titanium nitride film formed by ALD processes as taught inthe current disclosure, utilizing an alkyl-hydrazine as the nitrogensource, at a substrate temperature of 350° C. The eWF line labelled as220 indicates the eWF of a gate electrode structure comprising atitanium nitride film formed by ALD processes as taught in the currentdisclosure, utilizing an alkyl-hydrazine as the nitrogen source, at asubstrate temperature of 400° C. As shown in FIG. 3, the gate electrodestructures comprising a titanium nitride film formed by the ALDprocesses of the current disclosure (i.e., utilizing an alkyl-hydrazineprecursor) show a marked increase in eWF at reduced titanium nitridefilm thickness. For example, at a titanium nitride film thickness ofapproximately equal to or less than 20 Angstroms, the gate electrodestructures comprising titanium nitride films formed utilizing thealkyl-hydrazine precursor show an increase in eWF of greater than 200meV over the gate electrode structure comprising a titanium nitride filmformed utilizing the prior art ammonia precursor.

Therefore, in some embodiments of the disclosure, forming the transitionmetal nitride film by ALD using a transition metal precursor and analkyl-hydrazine precursor may comprise forming a gate electrodestructure comprising the transition metal nitride film to have aneffective work function greater than 4.2 eV, or even an effective workfunction greater than 4.4 eV. It should be noted that the embodiments ofthe disclosure allow for formation of gate electrode structurescomprising thin metal nitrides films with increased effective workfunction, for example, in some embodiments methods may comprise forminga gate electrode structure comprising a transition metal nitride filmwith a thickness of less than 50 Angstroms with an effective workfunction of greater than 4.8 eV. In further embodiments, methods maycomprise forming the gate electrode structure comprising a transitionmetal nitride film with a thickness of less than 30 Angstroms with aneffective work function of greater than 4.7 eV. In yet furtherembodiments, methods may comprise forming the gate electrode structureto comprise a transition metal nitride film with a thickness of lessthan 20 Angstroms with an effective work function of greater than 4.4eV.

As a non-limiting example, the transition metal nitride film comprisingthe gate electrode 310 may in some embodiment have a thickness of lessthan 50 Angstroms, or in some embodiments less than 30 Angstroms or evenin some embodiments less than 20 Angstroms.

The properties of the gate electrode 310 may also be further modified bythe ability to incorporate increased atomic percentages of carbon andhydrogen into the transition metal nitride film comprising the gateelectrode 310. For example, in some embodiments the transition metalnitride film comprising the gate electrode 310 may have an atomicconcentration of carbon greater than 0.1%, or greater than 1%, or evengreater than 10%. In addition, in some embodiments, the transition metalnitride film comprising the gate electrode 100 may have an atomicconcentration of hydrogen greater than 0.1%, or greater than 1%, or evengreater than 10%. In the embodiments outlined herein, the atomicconcentration of an element may be determined utilizing Rutherfordbackscattering (RB S).

Embodiments of the disclosure may also include a reaction systemconfigured to perform the methods of the disclosure. In more detail,FIG. 4 schematically illustrates a reaction system 400 including areaction chamber 402 that further includes mechanism for retaining asubstrate (not shown) under predetermined pressure, temperature, andambient conditions, and for selectively exposing the substrate tovarious gases. A precursor reactant source 404 may be coupled byconduits or other appropriate means 404A to the reaction chamber 402,and may further couple to a manifold, valve control system, mass flowcontrol system, or mechanism to control a gaseous precursor originatingfrom the precursor reactant source 404. A precursor (not shown) suppliedby the precursor reactant source 404, the reactant (not shown), may beliquid or solid under room temperature and standard atmospheric pressureconditions. Such a precursor may be vaporized within a reactant sourcevacuum vessel, which may be maintained at or above a vaporizingtemperature within a precursor source chamber. In such embodiments, thevaporized precursor may be transported with a carrier gas (e.g., aninactive or inert gas) and then fed into the reaction chamber 402through conduit 404A. In other embodiments, the precursor may be a vaporunder standard conditions. In such embodiments, the precursor does notneed to be vaporized and may not require a carrier gas. For example, inone embodiment the precursor may be stored in a gas cylinder. Thereaction system 400 may also include additional precursor reactantsources, such as a precursor reactant source 406, which may also becoupled to the reaction chamber by conduits 406A as described above.

A purge gas source 408 may also be coupled to the reaction chamber 402via conduits 408A, and selectively supplies various inert or noble gasesto the reaction chamber 402 to assist with the removal of precursor gasor waste gasses from the reaction chamber. The various inert or noblegasses that may be supplied may originate from a solid, liquid or storedgaseous form.

The reaction system 400 of FIG. 4, may also comprise a system operationand control mechanism 410 that provides electronic circuitry andmechanical components to selectively operate valves, manifolds, pumpsand other equipment included in the reaction system 400. Such circuitryand components operate to introduce precursors, purge gasses from therespective precursor sources 404, 406 and purge gas source 408. Thesystem operation and control mechanism 410 also controls timing of gaspulse sequences, temperature of the substrate and reaction chamber, andpressure of the reaction chamber and various other operations necessaryto provide proper operation of the reaction system 400. The operationand control mechanism 410 can include control software and electricallyor pneumatically controlled valves to control flow of precursors,reactants and purge gasses into and out of the reaction chamber 402. Thecontrol system can include modules such as a software or hardwarecomponent, e.g., a FPGA or ASIC, which performs certain tasks. A modulecan advantageously be configured to reside on the addressable storagemedium of the control system and be configured to execute one or moreprocesses.

Those of skill in the relevant arts appreciate that other configurationsof the present reaction system are possible, including different numberand kind of precursor reactant sources and purge gas sources. Further,such persons will also appreciate that there are many arrangements ofvalves, conduits, precursor sources, and purge gas sources that may beused to accomplish the goal of selectively feeding gasses into reactionchamber 402. Further, as a schematic representation of a reactionsystem, many components have been omitted for simplicity ofillustration, and such components may include, for example, variousvalves, manifolds, purifiers, heaters, containers, vents, and/orbypasses.

The example embodiments of the disclosure described above do not limitthe scope of the invention, since these embodiments are merely examplesof the embodiments of the invention, which is defined by the appendedclaims and their legal equivalents. Any equivalent embodiments areintended to be within the scope of this invention. Indeed, variousmodifications of the disclosure, in addition to those shown anddescribed herein, such as alternative useful combination of the elementsdescribed, may become apparent to those skilled in the art from thedescription. Such modifications and embodiments are also intended tofall within the scope of the appended claims.

What is claimed is:
 1. A semiconductor device structure comprising: aPMOS transistor gate structure, the PMOS gate structure comprising: atransition metal nitride film; a semiconductor body; and a gatedielectric disposed between the transition metal nitride film and thesemiconductor body; wherein the transition metal nitride film comprisesa predominant (200) crystallographic orientation, and wherein thetransition metal nitride film has atomic concentration of carbon greaterthan 10%.
 2. The semiconductor device structure of claim 1, wherein thetransition metal nitride film comprises titanium nitride.
 3. Thesemiconductor device structure of claim 1, wherein the transition metalnitride film has a thickness of less than 20 Angstroms.
 4. Thesemiconductor device structure of claim 1, wherein the PMOS gatestructure has an effective work function greater than 4.6 eV.
 5. Asemiconductor device structure comprising: a NMOS transistor gatestructure, the NMOS gate structure comprising: a transition metalnitride film; a semiconductor body; and a gate dielectric disposedbetween the transition metal nitride film and the semiconductor body;wherein the transition metal nitride film comprises a predominant (200)crystallographic orientation, and wherein the NMOS gate structure has aneffective work function greater than 4.7 eV.
 6. The semiconductor devicestructure of claim 5, wherein the transition metal nitride filmcomprises titanium nitride.
 7. The semiconductor device structure ofclaim 3, wherein the thickness of the transition metal nitride film isless than approximately 10 Angstroms.
 8. The semiconductor devicestructure of claim 4, wherein the effective work function of the PMOSgate structure is greater than approximately 4.8 eV.
 9. Thesemiconductor device structure of claim 1, wherein the transition metalnitride film has atomic concentration of hydrogen greater than 0.1%. 10.The semiconductor device structure of claim 9, wherein the transitionmetal nitride film has atomic concentration of hydrogen greater than 1%.11. The semiconductor device structure of claim 10, wherein thetransition metal nitride film has atomic concentration of hydrogengreater than 2%.
 12. The semiconductor device structure of claim 11,wherein the transition metal nitride film has atomic concentration ofhydrogen greater than 10%.
 13. The semiconductor device structure ofclaim 5, wherein the transition metal nitride film has a thickness lessthan 50 Angstroms and wherein the NMOS gate structure has an effectivework function greater that 4.8 eV.
 14. The semiconductor devicestructure of claim 5, wherein the transition metal nitride film has athickness less than 30 Angstroms.
 15. The semiconductor device structureof claim 5, wherein the transition metal nitride film has atomicconcentration of carbon greater than 10%.
 16. The semiconductor devicestructure of claim 5, wherein the transition metal nitride film hasatomic concentration of hydrogen greater than 0.1%.
 17. A semiconductordevice structure comprising: a transistor gate structure, comprising: atitanium nitride film; a semiconductor body; and a gate dielectricdisposed between the titanium nitride film and the semiconductor body;wherein the titanium nitride film comprises a predominant (200)crystallographic orientation, wherein the titanium nitride film has athickness of less than 20 Angstroms, and wherein the transistor gatestructure has an effective work function greater than 4.6 eV.
 18. Thesemiconductor device structure of claim 17, wherein the titanium nitridefilm has atomic concentration of carbon greater than 10%.
 19. Thesemiconductor device structure of claim 17, wherein the titanium nitridefilm has atomic concentration of hydrogen greater than 0.1%.
 20. Thesemiconductor device structure of claim 19, wherein the titanium nitridefilm has atomic concentration of hydrogen greater than 2% and whereinthe transistor gate structure has an effective work function greaterthan 4.7 eV.